The primary purpose of a guitar strap worn over the shoulder is to suspend the guitar securely in front of the guitar player. The length of the strap should be adjustable to allow for various combinations of guitar sizes, user heights, and playing positions. The ideal guitar strap is easy to attach and detach from the guitar, holds the guitar securely while attached, can be adjusted in length quickly and easily, is free from hard or rough edges that can scratch the guitar's surface, doesn't put any unnecessary torque or stress on the guitar, and is comfortable to wear for extended periods.
Currently, the most common guitar straps are made from a band of fabric or leather with ends containing slits which are pressed over the guitar's strap-buttons to connect the strap to the guitar. The means of adjusting the length of the strap is typically via a sliding buckle. One end of the strap is fixed to a slit-connector while a free end of the strap is threaded through the buckle. In order to slide the buckle's position, the user has to take the guitar off, loosen the threaded portion of the strap, adjust the length, and then put the guitar back on. The adjustment process is repeated until the desired overall length is achieved.
These common straps have significant drawbacks. A first drawback results from the means of connecting to the guitar via a slit in a piece of material, which is very often leather (or simulated leather). If the slit is too small, it is difficult to press the connecting piece over the guitar's strap-button. This is especially true when the connecting piece is made from thicker and less-pliable material. Sometimes significant force is required to press and pry the slit over the button head. This can place stress on the body of the guitar near the base of the button which can cause the button to strip out of its threads in the body, create localized cracks in the body material, or in some cases rip the button completely out. Conversely, if the slit is too big, the connection will not be as secure which can cause the connection piece to pull off of the strap-button unexpectedly, allowing the guitar to fall onto the ground and get damaged.
There are several different designs which have attempted to remedy these connection issues, and most fall under the category of ‘locking’ guitar straps. They typically feature some sort of mechanism which opens to receive the guitar's strap-button and closes tightly behind the button head. One example is found in U.S. Pat. No. 6,590,145 B2 which utilizes a keyhole in the connecting piece. A flexible tongue applies pressure to the button head to help keep it down in the narrow section of the keyhole. This design benefits from simplicity. However, with the fixed keyhole size, this strap attachment is limited in the variations of strap-button shapes and sizes it can accept. Another example is found in U.S. Pat. No. 7,888,572 B2 which has a lock-body to receive the button and a retainer latch to hold the button within the lock-body. The primary problem with this strap and strap attachment means is the fixed size of the lock-body, which again limits the variations of strap-buttons it can accept. Further, this strap utilizes multiple small components such as a pin, a spring, and a latch, which must be made from hard materials. If the chosen material is metal, there is risk of scratching the guitar. If the material is plastic, it must be sufficiently strong to hold its shape with even the heaviest of guitars while avoiding fatigue and stress failure. Still another example is found in U.S. Pat. No. 7,818,851 B2 which has a sleeve with a keyhole that receives the button and a slider which slides down behind the button head. This design, like Rosenberg's, benefits from a relatively simple design. However, like the others, it has a fixed keyhole size which limits compatible strap-buttons.
The second set of issues for common guitar straps result from the means of guitar strap length adjustment. Having to remove the guitar to adjust strap length is inconvenient and increases the risk of dropping the guitar. Additionally, since the user isn't wearing the strap during adjustment, it is difficult to tell how much adjustment is needed and multiple adjustments are often required to get the desired length. Finally, there are certain lengths that set the hard buckles in positions which will come in contact with the shoulder, leading to discomfort. U.S. Pat. No. 7,491,876 improves upon this by utilizing hook-and-loop fasteners on the strap ends, while also including a shoulder pad to help increase comfort. However, the free end of the strap with the thumb tab is on the bottom, padded side of the strap. This makes it somewhat awkward to grab the thumb tab and reposition the free end somewhere along the bottom surface. Additionally, the adjustable range is limited due to the user's body and the addition of the flexible cushioning pad.